Parasitic electrical draw

[ctbiker12]

I have a 1986 Four Winns Freedom 160 with a Mercruiser 140 hp - 4 cyl engine. I purchased the online manual on iboats and have been very happy with the information. My problem is an electrical draw. Last season I changed the starter solenoid and found I had loose connections on the alternator. I replaced the connections and the alternator is charging the battery but there is a draw. This past weekend I attempted to find the draw by removing one wire at a time. The draw went away when I removed the small red wire from the alternator. I traced the wire and find that it goes to a connector with three (3) red wires coming off of it. One wire goes to the circuit breaker (which I replaced as a precaution), one wire goes to the ammeter (I think) and the third wire goes to the starter solenoid. I removed each wire (except the one to the solenoid) and there was no change in the draw (about 3.6 amps). The manual says that I have a second solenoid somewhere but I don't know where to look to check it. Any thoughts would be greatly appreciated.

 

[achris]

Re: Parasitic electrical draw

Welcome to iBoats.

First off, I suspect the manual you're using is an on-line seloc... bad news. They are full of incorrect and misleading information.

HERE is a proper manual for you to download.

The draw went away when I removed the small red wire from the alternator.

Your problem sounds like a faulty exciter diode or regulator inside the alternator.

Chris....

 

[Don S]

Re: Parasitic electrical draw

Take your alternator to your local Starter/Alternator/Electric Motor repair shop and have them check it out and fix it. It will be a lot cheaper and better than all the cheap aftermarket new junk out there.

 

[ctbiker12]

Re: Parasitic electrical draw

First off, I suspect the manual you're using is an on-line seloc... bad news. They are full of incorrect and misleading information.

Thank you for the manual and information. The manual link led me to the exact manual I have. I got it from a previous link on iboats.com but at least now I know I have a good manual.

Your problem sounds like a faulty exciter diode or regulator inside the alternator.

Chris....

I will remove the alternator and have it checked out by a local marine guy and let people know what happened. Thanks again,

 

[Don S]

Re: Parasitic electrical draw

I will remove the alternator and have it checked out by a local marine guy and let people know what happened. Thanks again,

Not a marine shop, take it to a local starter/alternator shop. That is what they do, marine shops just change parts, and don't usually have the necessary tools to properly rebuild a starter or alternator.

 

[ctbiker12]

Re: Parasitic electrical draw

I took the alternator to an electrical shop and it checked out fine. The tech said that the red wire is a sensing wire and it it sensing current and when everything is off, it should not sense anything so the draw is still there. I traced the wires back to the ignition, pulled the ignition fuse and the draw remains. I have ruled out everything on the dashboard. the manual says there is a slave solenoid as well as a starter solenoid. I cannot find the slave solenoid anywhere in the boat. Still looking!

 

[cecho]

Re: Parasitic electrical draw

If there is a slave solenoid then you should be able to follow the wire from the starter solenoid to find it. If you don't have one the wire should just go to the ignition switch.

Have you tested the trim solenoids for current draw? What about the other electrical devices on board? Bilge pump, bilge fan, radio, fish finder, etc...

 

[achris]

Re: Parasitic electrical draw

OK.. so the alternator's ok... But the draw still only goes away when you disconnect the wire from the alternator... ergo. the alternator is drawing the current. Yes?

Yes... so. I had a look at the wiring diagrams. No red wire on the alternator! There should be 4 wires, a large orange (output), large black (ground), a purple (excitation) and a red/purple (sense). Now, the excitation wire should only have power on it when the key is ON, and it SHOULD be drawing power. If that wire has power on when the key is OFF, you have the excitation and sense wires reversed....

Chris......

 

[ctbiker12]

Re: Parasitic electrical draw

You are correct about the 4 wires. Orange to solenoid, ground, purple and red (supposed to be red/purple but someone before me must have had a bad section of wire. I swapped the red (which is red/purple at the opposite end) with the purple wire and the draw tripled. It went from 5.6 mv to 15.8 mv so I swapped them back. The alternator shop suggested that I replace the alternator with a new delco marine alt. which only has the orange and black. He said the exciter and sense are not really needed. He said he would give me instructions on what to do with those wires when I install the new alt. Still, it is baffling. I eliminated everything else on the boat one by one, it seems to only be in the starter /solenoid / alt. loop.